Analysis of cyclone separator solutions depending on spray ejector condenser conditions

Abstract

• A novel technique to capture CO 2 including SEC and cyclone separator. • Investigating full condensation within SEC via experimental and analytical modeling. • Studying the effect of cone size on the performance of cyclone separator. • Effects of non-condensable gas (CO2) on the efficiency of cyclone. • Influence of droplet breakup within the SEC on the separation efficiency of cyclone. The core design strategy for minimizing CO 2 emissions in gas power plant entails combining a spray ejector condenser (SEC) and separator to accomplish steam condensation and CO 2 purification. This innovative process involves direct-contact condensation of steam with CO 2 , facilitated by interaction with a subcooled water spray, along with a cyclone separator mechanism intended for generating pure CO 2 . The investigation of the SEC section, both experimentally and analytically, provides crucial insights into its operational dynamics. Given the susceptibility of cyclone efficiency to fluctuations in SEC conditions, this research endeavors to examine the impacts of CO 2 volumetric flow rate and droplet break-up within the SEC on the separation efficacy of the cyclone separator. Additionally, the impact of cone size on the performance of the cyclone has been investigated. Here, a three-dimensional, transient, and turbulent cyclone separator is numerically simulated using Ansys Fluent 2021 R1. The Reynolds Stress Model is employed to simulate turbulent flow, while a mixture model is utilized to replicate swirl two-phase flow within the separators. The findings revealed that reductions in steam and CO 2 flow rates were associated with a decrease in outlet temperature but an increase in SEC inlet temperature, leading to a rise in temperature difference and heat transfer rate. Furthermore, an augmentation in cyclone cone size (from 0.2 to 0.5 m) resulted in enhanced separation efficiency (from 77.30 % to 80.98 %) alongside an elevation in pressure drop (from 6.08 Pa to 10.91 Pa), suggesting a compromise between CO 2 purification and energy consumption. Additionally, elevated CO 2 flow rates induced a rise in pressure drop and separation efficiency, ultimately achieving maximum efficiency at a rate of 24 g s . Moreover, the exploration into droplet breakup manifesting in a boost in separation efficiency from 50.98 % to 100 % across droplet diameters ranging from 1 to 20 μ m .

Topics & Concepts